NASA Earth Observatory image created by Robert Simmon, using Landsat data provided by the United States Geological Survey. Caption by Adam Voiland, with information from Thomas Veblen and Bill Romme.

Now, the exact same location just six years later.

NASA Earth Observatory image created by Robert Simmon, using Landsat data provided by the United States Geological Survey. Caption by Adam Voiland, with information from Thomas Veblen and Bill Romme.

Where did the green go? What happened to the forest? Pine bark beetles happened.

These rice-sized insects have been attacking five-needle pine trees across the western U.S. for the past decade, causing widespread losses to forests across the Rocky Mountains and beyond. The U.S. Forest Service estimates that 100,000 trees in northern Colorado and southern Wyoming die each day.

This is a big problem. Actually, more than big, as many scientists call the situation an epidemic. The affected pine trees provide homes for many wildlife species, food for others (grizzly bears!) and stabilize snowpacks and soil overall.